Improvement in adjusting spieit-levels



CHAPIN & STANLEY.

Spirit Level.

Patented Sept. 10, 1867.

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SAMUEL N. GHAPIN AND AUGUSTUS STANLEY, O'F-NEW BRITAIN, CON- N EGTICUT.

LettersPatent No. 68,603, dated September 10, 1867,

IMPROVEMENT TN ADJUSTING SPIBIT-LBVEI JS.

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TO ALL. WHOM IT MAY CON OERN:

Be it known that we, SnnnELN. CHAPIN and Aueusrus STANLEY, both of NewBritain, in the county of Hartford, and State of Connecticut, haveinvented certain new and useful Improvements in the Construction ofPlumb and Level-Indicators; and we do hereby declare that the followingis a full and exact description thereof. I

Our invention relates to the means for adjusting the positions of theindicator in the structure so as to correct any slight derangements dueto warping or othcr eauses. This has been attempted heretofore, butveryimperfectly. I v

We will first describe what we consider the best means of carrying outour invention, and will afterwards designate the points which we believeto be new. The. accompanying drawings form a part of this specification.

Figure 1 is an edge view, and

Figure 2 a longitudinal section.

Similar letters of reference indicate like parts in all the figures.

The drawings represent the novel parts, with so much of the other partsas is necessary to indicate their relation thereto. v

A is a. piece of cherry carefully seasoned, and adapted to form. thebody of the plumb and level-indicator. It is mortised to receive theplumbing and levelling devices. These devices may be made as usual, byenclosing small quantities of air with alcohol in glass tubes. The samegeneral mode of constructing and adjusting may be applied to bothdevices. B is the long glass, which is made available when the device isusedfor adjusting levels, and D is the shorter tube, which is availablewhen the device is used for adjusting a perpendicular. line. Some of thefeatures of our invention are represented as applying to only one, andothers to both 'of these glasses, for the purpose of adjusting them. Thelong glass B is firmly fixed in a metallic case, C, which presents asurface, 0, at each end, adapted to receive the screws 0, which hold thesurface 0 flush or about flush with the adjacent surfaces of theinstrument. Under one or both of the overhanging ends 0 we placesquantity of goodvulcanized rubber, as indicated by M. By turning one orboth the screws 6 the position of the case C and the contained glass maybe adjusted relatively to the body A. Thus, by driving the screwin ateither end the rubber at that end will be compressech and the glass thusvaried in its position; or, if the same screw be slaeked the rubber Mbeneath will expand by its elasticity and adjust the glass in theopposite direction. The short glass D is fixed in a casc, E, which turnson the pivot-f. There is a stout arm, E, which stands at right angleswith the glass D, and through which the adjustment is effected. Thescrew G, introduced from the edge of the body A, acts on theright-angled arm E, and by compressing and by varying the position (ifthe latter the short glass D is adjusted at will.

We do not consider it essential to the success of our invention that thematerial of the body A shall be cherry or other wood, or that thelevelling devices B and D, or the other parts, shall be constructedexactly in the form and with the proportions represented. Manymodifications will be suggested byany good mechanic. It is practicableto employ other materials, as gutta percha, leather, or felt, in placeof the rubber M, but we esteem it important that the material thereemployed shall be not only elastic, but shall extend uniformly acrossand ofer its resistance evenly over a considerable surface, so as toprevent the device from rocking and twisting.

Having now fully described our invention, what we claim as new ininstruments for determining levels and the like, is as follows: V

1. We claim a bed of vulcanized rubber, M, or equivalent elasticmaterial, arranged relatively to the adjusting-screw c, and to theadjustable levelling device ]3 or D, substantially as and for thepurpose herein specified.

2. We claim constructing the case E, which carries the short glass D,with a part, E, or its equivalent, standing at right angles to the glassD, in combination with means for adjusting the same, operated at theedge of the body A, substantially as and for the purpose hereinspecified.

SAMUEL N. GHAPIN,

AUGUSTUS STANLEY.

Witnesses O. E. MmcunLL, A. H. STANLY.

